1. Technical Field
The present invention relates to graphene transistors, and more particularly to systems, apparatuses and devices incorporating graphene transistors with self-aligned gates, and methods of their fabrication.
2. Description of the Related Art
Graphene is a material that has been studied for both scientific and technological applications due to its unique electronic properties. Specifically, the high mobility of charge carriers in graphene combined with the ability to modulate its carrier concentration by an external electric field renders graphene-based field-effect transistors (GFETs) promising candidates for high frequency applications. For example, graphene (field-effect transistors) FETs have been demonstrated to operate at cut-off frequencies as high as 300 GHz. Additional increases in fT may be achieved through further development of the constituent device materials and the device design.
For conventional silicon-based FETs, an important design concern is resistance in access regions between the gate and source/drain of the devices. The access resistance is reduced by doping the ungated access regions through ion implantation to create a self-aligned structure. Specifically, an insulating sidewall (spacer) surrounding the gate stack is created, followed by the formation of highly-doped source/drain regions by ion implantation and thermal activation.